Security readout for executives and security teams
Plain-English summary
CVE-2021-37453 is a stored cross-site scripting issue in NCH Axon PBX v2.22 and earlier. A malicious extension name could be saved and later displayed to another user, potentially running script in that user’s browser. Business urgency depends on whether Axon PBX is deployed and who can create or edit extension names.
Executive priority
Treat this as a targeted application risk, not an internet-scale emergency based on the supplied evidence. Prioritize quickly if Axon PBX is used for business telephony or administered by privileged users.
Technical view
The CVE describes stored XSS in NCH Axon PBX v2.22 and earlier through the extension name field. The record provides no CVSS score, CWE, detailed affected CPEs, vendor advisory, patch version, or named mitigation. A public GitHub proof-of-concept reference exists, but the provided sources do not support active exploitation.
Likely exposure
Likely exposure is limited to organizations running NCH Axon PBX v2.22 or earlier, especially where untrusted or lower-privileged users can set extension names viewed by administrators or operators.
Exploitation context
The sources indicate a public proof-of-concept reference, so defenders should assume technical details may be accessible. KEV is false, and the supplied sources do not claim active exploitation in the wild.
Researcher notes
The record is sparse: severity, CVSS, CWE, CPEs, patch status, and vendor advisory details are absent. Analysis is based mainly on the CVE description and public reference. Avoid overclaiming exploitation or remediation beyond vendor guidance.
Mitigation direction
- Inventory NCH Axon PBX deployments and identify versions v2.22 or earlier.
- Check NCH guidance for fixed versions or supported upgrade paths.
- Restrict who can create or edit extension names until remediated.
- Review whether PBX administration is exposed beyond trusted networks.
- Monitor PBX administration sessions for unexpected browser-side behavior.
Validation and detection
- Confirm whether NCH Axon PBX is present in asset inventory.
- Verify installed Axon PBX versions against the v2.22-and-earlier scope.
- Review extension name handling for proper output encoding in a controlled environment.
- Check whether untrusted users can modify extension names.
- Document compensating controls if no vendor fix is available.
Public sources used
Generated from the cited source records. This long-tail analysis has not been individually reviewed by a named human.
Conservative CVE-to-ATT&CK context
These mappings and lookup hints may be relevant to the vulnerability behavior, CWE, affected product, or exposure path. Glexia-inferred context is not an official MITRE, ATT&CK, CWE, or CVE Program mapping.
ATT&CK lookup starting points
Use these exact CWE pages and searches to review the Glexia ATT&CK library from this CVE's weakness and description context.
CVE-2021-37453 mapping review
Open the CVE-to-ATT&CK bridge for reviewed, inferred, or future official mappings tied to this CVE.
Open ATT&CK lookup- Severity
- Unknown
- CVSS
- Not scored
- Known Exploited
- No
- Published
CNA and ADP enrichment extracted from CVE v5
These fields come from the CVE record and ADP containers, not from Glexia's Take. They preserve time-varying source decisions such as CISA SSVC, KEV status, CVSS metrics, and provider references.
CVSS and timeline data
No CVSS vectors or timeline events were available in the normalized CVE source material.
Source materials
- CVE List V5 sourceCVE List V5
- https://www.nch.com.au/pbx/index.htmlCVE reference · x_refsource_MISC
- https://github.com/0xfml/poc/blob/main/NCH/Axon_2.22_XSS.mdCVE reference · x_refsource_MISC
Products and packages named in the record
CWE details
CWE links open Glexia weakness intelligence pages with official CWE context, developer remediation guidance, and related CVE mappings.